The present invention relates to a magnetic head for detecting the signal magnetization recorded in a magnetic recording medium by making use of the magneto-resistive effect and, more particularly, to a magnetic disk drive thin film head for reading the signals recorded in a high track density, efficiently with low noises.
The magnetic disk drive head of the prior art has been used as a self read-write head for reading and writing operations with a common head. In order to satisfy the demand for improved linear density and higher performance magnetic head, it is necessary to make independent and optimize the write head and the read head. This concept of separate write and read heads has already been well known in the audio tape or the magnetic filing tape (MT) system of the prior art. Since each of these has a track width of several hundreds of microns or more, the format cannot be used for a magnetic disk drive.
An example of a head suitable for a high efficiency read operation that uses magneto-resistance is disclosed in Japanese Patent Laid-Open No. 101411/1978.
The magneto-resistive type head cannot be used with magnetic tapes of the prior art because of large read output fluctuations that occur when the track width is reduced. This problem arises for the following reason: As the track width of magneto-resistive magnetic film is reduced, its magnetic domain does not become single but establishes a domain wall having no reproductivity so that the so-called "Barkhausen noises" are generated.